let's say I have a string in which the words are separated by 1 or more spaces and I want to use that string in and SQL LIKE condition. How do I make my SQL and tell it to match 1 or more blank space character in my string? Is there an SQL wildcard that I can use to do that?
Let me know
If you're just looking to get anything with atleast one blank / whitespace then you can do something like the following WHERE myField LIKE '% %'
If your dialect allows it, use SIMILAR TO, which allows for more flexible matching, including the normal regular expression quantifiers '?', '*' and '+', with grouping indicated by '()'
where entry SIMILAR TO 'hello +there'
will match 'hello there' with any number of spaces between the two words.
I guess in MySQL this is
where entry RLIKE 'hello +there'
I know this is late, but I never found a solution to this in relation to a LIKE question.
There is no way to do what you're wanting within a SQL LIKE. What you would have to do is use REGEXP and [[:space:]] inside your expression.
So to find one or more spaces between two words..
WHERE col REGEXP 'firstword[[:space:]]+secondword'
Another way to match for one or more space would be to use [].
It's done like this.
LIKE '%[ ]%'
This will match one or more spaces.
you can't do this using LIKE but what you can do, if you know this condition can exist in your data, is as you're inserting the data into the table, use regular expression matching to detect it up front and set a flag in a different column created for this purpose.
I just replace the whitespace chars with '%'. Lets say I want to do a LIKE query on a string like this 'I want to query this string with a LIKE'
#search_string = 'I want to query this string with a LIKE'
#search_string = ("%"+#search_string+"%").tr(" ", "%")
#my_query = MyTable.find(:all, :conditions => ['my_column LIKE ?', #search_string])
first I add the '%' to the start and end of string with
("%"+#search_string+"%")
and then replace other remaining whitespace chars with '%' like so
.tr(" ", "%")
http://www.techonthenet.com/sql/like.php
The patterns that you can choose from are:
% allows you to match any string of any length (including zero length)
_ allows you to match on a single character
I think that the question is not asking to match any spaces but to match two strings one a pattern and the other with wrong number of spaces because of typos.
In my case I have to check two fields from different tables one preloaded and the other filled typed by users so sometimes they don't respect 100% the pattern.
The solution was to use LIKE in the join
Select table1.field
from table1
left join table2 on table1.field like('%' + replace(table2.field,' ','%')+'%')
if the condition:
WHERE myField LIKE '%Hello world%'
doesn't work try
WHERE myField LIKE '%Hello%'
and
WHERE myField LIKE '%world%'
this approach is helpful in a few specific use cases, hope this helps.
Related
I have a small mysql database with a column which has format of a field as following:
x_1_1,
x_1_2,
x_1_2,
x_2_1,
x_2_12,
x_3_1,
x_3_2,
x_3_11,
I want to extra the data where it matches last '_1'. So if I run a query on above sample dataset, it would return
x_1_1,
x_2_1,
x_3_1,
This should not return x_2_12 or x_3_11.
I tried like '%_1' but it returns x_2_12 and x_3_11 as well.
Thank you!
A simple method is the right() function:
select t.*
from t
where right(field, 2) = '_1';
You can use like but you need to escape the _:
where field like '%$_1' escape '$'
Or use regular expressions:
where field regexp '_1$'
The underscore character has special significance in a LIKE clause. It acts as a wildcard and represent one single character. So you would have to escape it with a backslash:
LIKE '%\_1'
RIGHT does the job too, but it requires that you provide the proper length for the string being sought and is thus less flexible.
Duh, I found the answer.
Use RIGHT (col_name, 2) = '_1'
Thank you!
E.g :
I have 1 word for search the data. And the word is 'ayam'.
And this is my query :
select nama_product from product where nama_product like %a%
It works fine. But it show the record that i dont want to be showed.
This is the result :
ayam bakar
daging ayam
bayam hijau
daun bayam
The first and the second result is okay. But the third and the last that i dont want to be showed.
Because i want to show 'ayam' not "b'ayam'"
How do i handle this? I don't know it is duplicate or not. Because i already search it but i didn't find.
If you need to search the word 'ayam' without any prefix and sufix character, you would better use regular expression for that .
e.g.,
SELECT namma_product FROM product WHERE namma_product REGEXP 'ayam'
try this. This will work
Unfortunately this is a limitation of SQL. Some SQL databases have advanced text searching functions such as regular expressions which allow very specific text results.
For your case you will likely have to perform multiple LIKE conditions. For example:
select nama_product
from product
where
nama_product like 'ayam %'
or nama_product like '% ayam %'
or nama_product like '% ayam'
or nama_product = 'ayam'
Please note that if the text fields are very large or if the table is large, queries that rely on LIKE operators can become very slow. LIKE does not scale well with large datasets. If this is a dataset you think will become very large in the future, best to design it in a way where the LIKE operator will not be needed.
You can use regex to match only whole words:
select nama_product
from product
where nama_product regexp '(^| )ayam( |$)';
(^| ) means the word must be the start of the string, or it must be preceded by a space
ayam is the word we're matching
( |$) means the word must be followed by a space, or it must be the end of the string
SQL Fiddle
when u insert '%' before and after it mean All Character before(after) your keyword so just change how u want
for example just keywords start with "ayam":
select nama_product from product where nama_product like 'ayam%'
another example just keywords ended with "ayam":
select nama_product from product where nama_product like '%ayam'
and after that look here ithink your answer is here :
Match only entire words with LIKE?
I want to remove the names which may be registered with fake names.
As the developer forgot to put validation on form registration.
Now i want to remove the fake names.
And for checking if that name is fake or not, I am checking if the name content any numbers or not ?
This is my query which i have written but its not working...
SELECT registration.regi_id, student.first_name,
student.cont_no, student.email_id,
registration.college,
registration.event_name,
registration.accomodation
FROM student, registration
WHERE student.stud_id = registration.stud_id
AND student.first_name NOT RLIKE '%[0-9]%'
How to fix this problem ?
Sorry for my language issues,
P.S.
There are many names in "first_name" field like "asdfasdf12323", i don't want that kind of names to be shown on list.
Your column may contain Alphanumeric characters also.YOu need to filter Numbers and Alphanumeric characters both
For Alphanumeric characters Try REGEXP '^[A-Za-z0-9]+$'
For numbers Try REGEXP '[0-9]'
Well as far as the regex is involved, your expression is only looking for a single number. Also, your 'NOT RLIKE' isn't using regex but is doing a basic string search for the literal '[0-9]' I believe. MySql has support for regex, and your last clause would look like so: AND student.first_name NOT REGEXP '[0-9]*'
I need a MySQL pattern to match a number, followed by a question mark.
I need something like
... like '%[0-9]?%'
but I have no idea how to create this regular expression.
http://dev.mysql.com/doc/refman/5.0/en/pattern-matching.html does not help.
Thanks!
you could try this:
SELECT * FROM YourTable WHERE YourField REGEXP '[0-9]\\?'
That will return rows where YourField contains a number followed by a ? anywhere in the value.
If you want it to only match if the whole field is a number followed by a ?. I.e. 9? then you could use this regex instead:
^[0-9]\\?$
I guess you're looking for something like this:
select * from table
where field rlike '[0-9]\\?'
Remember to escape the question mark. Otherwise, it will make the number optional.
Source.
I have table with rows of strings.
I'd like to search for those strings that consists of only
two words.
I tried few ways with [[:space:]] etc but mysql was returning
three, four word strings also
try this:
select * from yourTable WHERE field REGEXP('^[[:alnum:]]+[[:blank:]]+[[:alnum:]]+$');
more details in link :
http://dev.mysql.com/doc/refman/5.1/en/regexp.html
^\w+\s\w+$ should do well.
Note; what I experience more often in the last days is that close to nobody uses the ^$-operators.
They are absolutely needed if you want to tell if a string starts or ends with something or want to match the string exactly, word for word, as you. "Normal" strings, like you used (I assume you used something like \w[:space]\w match in the string, what means that they also match if the condition is true anywhere within the string!
Keep that in mind and Regex will serve you well :)
REGEXP ('^[a-z0-9]*[[:space:]][a-z0-9]*$')